Smooth muscle cell proliferation in the ductus arteriosus and the descending aorta, and effects of enalapril on SMC proliferation in perinatal rats

This study was carried out to determine the proliferation profile of the smooth muscle cells (SMC) in the media of the ductus arteriosus (DA) and the descending aorta (Ao), and to examine the effects of the angiotensin-converting enzyme inhibitor enalapril on the proliferation of these cells in perinatal rats. The proliferating cell nuclear antigen (PCNA) index of the DA peaked in 19-day-old fetuses at 75%, and the index significantly declined in 20-day-old fetuses. The PCNA index of the Ao showed a similar profile until pups reached 1 day of age; however, the index of the Ao then increased in 3-day-old pups. The PCNA indices of the DA and Ao decreased significantly after maternal oral treatment with enalapril (10 mg/kg for 7 days), with a more marked decline in the DA than in the Ao. The PCNA indices of these vessels in 20-day-old fetuses were not altered by maternal treatment with enalapril. These results indicate that the SMC proliferation rate in the DA was similar to that in the Ao until pups reached the age of 1 day, and that the inhibitory effect of enalapril on the SMC proliferation was age-dependent and more prominent in the DA than in the Ao.     

Effects of TAK-044, a nonselective endothelin receptor antagonist, on the spontaneous and indomethacin- or methylene blue-induced constriction of the ductus arteriosus in rats

We studied the effects of TAK-044, a nonselective endothelin (ET) receptor antagonist, on the indomethacin- or methylene blue-induced constriction of the ductus arteriosus (DA) in rats and compared them with the effects on spontaneous DA constriction. Injection of TAK-044 into 21-day-old fetuses in utero was performed through the uterine wall of laparotomized mother rats under light ether anesthesia. The fetuses were autopsied 3 hr after treatment with TAK-044 (10 mg/kg) in utero and simultaneous administration to the laparotomized mother rats of indomethacin (3 mg/kg, p.o.) or methylene blue (100 mg/kg, i.p.). In the second experiment, pregnant rats were decapitated on day 21 of gestation to obtain newborn rats by cesarean delivery. Newborn rats which were given TAK-044 (2, 10 mg/kg) immediately after or 1 hr before cesarean delivery were autopsied at various times after birth. In both experiments, pups were rapidly frozen in an acetone-dry ice mixture at autopsy to evaluate the DA constriction by the whole-body freezing and shaving method. TAK-044 injection into the fetus 3 hr before autopsy completely inhibited the DA constriction induced by maternal treatment with indomethacin or methylene blue. TAK-044 caused dose-dependent inhibition of the spontaneous closure of the DA after birth. The inhibitory effect was more pronounced in pups which were given TAK-044 in utero 1 hr before birth; however, the inhibitory effect was incomplete in newborn pups. These results, together with the previous finding that BQ-123, an ETA-specific receptor antagonist, inhibits the ductal constriction induced by oxygen in vitro [Coceani et al., 1992], indicate that the ETA receptor plays a significant role in the indomethacin- or methylene blue-induced DA constriction as well as in the spontaneous DA constriction after birth, and also indicate that the inhibition of ETA receptor by TAK-044 was more easily achieved in fetuses than in neonates.     

Involvement of oxygenase confers higher resistance to neonicotinoid insecticides in estuarine resident sand shrimp Crangon uritai than in kuruma prawn Penaeus japonicus and mysid Americamysis bahia

Fisheries Science - Globally, neonicotinoid contamination in aquatic environments, including estuarine areas, is a prevailing environmental concern. The estuarine resident marine crustacean sand...     

Comparison of heat production and plasma lipid metabolites between meat- and egg-types of Nagoya breed chicken during embryonic development

We compared heat production (HP) and plasma lipid metabolites between meat‐ and egg‐types of Nagoya breed chickens during embryonic development. To investigate HP and respiratory quotient, oxygen consumption and carbon dioxide production were measured using an open‐circuit calorimeter system. HP was significantly lower in meat‐ than in egg‐type chickens during embryonic development, and HP gradually decreased with developmental stage in both types. The respiratory quotient was constant at approximately 0.68 at every embryonic stage investigated, and the value was similar in both types. Plasma concentrations of triacylglycerol, nonesterified fatty acid, glycerol and D‐3‐hydroxybutyrate, which are associated with lipid metabolism, were similar in both types during embryonic development. These results demonstrate that chicken embryos selected for rapid growth of Nagoya breed have characteristic lower HP, and that when selecting chickens for rapid growth, HP is an important parameter during embryonic stages.     

Heat-shock-induced tetraploid and diploid/tetraploid mosaic in pond loach, Misgurnus anguillicaudatus

Tetraploid fish, which are considered as key resources of diploid gametes for further breeding and ploidy manipulation, can be artificially induced by inhibition of the mitotic cell division with hydrostatic pressure or temperature treatments. Although many attempts have been made to induce artificial tetraploid strains, successful establishment of viable and fertile tetraploid strains are rare. In pond loach, Misgurnus anguillicaudatus, natural tetraploid individuals are distributed in wild populations and diploid gametes from the tetraploid fish have been used for the induction of polyploid individuals, but artificially induced tetraploid strains have not been established yet. In the present study, we optimised starting timing of the heat-shock treatment (41 °C for 2 min) to inhibit a mitotic cell division in fertilised eggs of the normal diploid pond loach between 21 and 51 min after insemination at 20 °C. After the treatment, we observed external appearance of hatching larvae and flow cytometrically determined ploidy status of the resultant larvae. Although tetraploid and diploid/tetraploid mosaic larvae were obtained, the optimum timings for induction of tetraploidy varied amongst crosses. Various kinds of ploidy such as haploidy, diploidy, triploidy, pentaploidy, hexaploidy, aneuploidy and mosaic were detected in non-optimum heat-shock timings for tetraploidisation. Survivors, a tetraploid and a diploid/tetraploid mosaic male, matured at the age of 1-year-old, but they produced functional haploid spermatozoa.     

Production of a transgenic pig expressing human albumin and enhanced green fluorescent protein

We introduced a fusion gene of human albumin and enhanced green fluorescent protein (EGFP) into porcine oocytes using the sperm vector method, and produced a piglet that showed clear expression of GFP in the hooves and skin. PCR and Southern blotting analysis of genomic DNA extracted from the piglet's tissues, including the liver, showed that the tissues carried the transgene. RT-PCR analysis demonstrated that both the human albumin and EGFP genes were expressed in the tissues. The fact that human albumin gene was integrated and expressed in the liver of the transgenic pig opened a way for us to achieve our goal, which was the use of transgenic pigs for the bioartificial liver support system.     

Synthesis and insecticidal and acaricidal activity of new N-(α-substituted phenoxybenzyl)-4-pyrimidinamines

A new class of insecticides and acaricides containing N-(α-substituted phenoxybenzyl)-4-pyrimidinamines as core structure were synthesized and their insecticidal and acaricidal potencies assessed. Among these, both the N-(3 or 4-phenoxybenzyl)-4-pyrimidinamine showed remarkable activity against diamondback moth, Plutella xylostella L., brown rice planthopper, Nilaparvata lugens (Stal) and two-spotted spider mite, Tetranychus urticae Koch. The potency of the new pyrimidinamines was particularly increased when a methyl, ethyl, iso-propyl, or cyclopropyl group was introduced at the α-position of benzyl moiety and it was evident that a single (+) optical isomer is more active than its antipode. Structure-activity relationships are discussed.     

Levels and Chemical Forms of Heavy Metals in Soils from Red River Delta, Vietnam

Levels and chemical forms of heavy metals in forest, paddy, and upland field soils from the Red River Delta, Vietnam were examined. Forest soils contained high Cr and Cu levels that were higher in subsurface than in surface layers. Levels of Cu, Pb, and Zn that exceeded the limits allowed for Vietnamese agricultural soils were found in the surface layer of a paddy field near the wastewater channel of a copper casting village. High amounts of Zn accumulated in the surface soil of paddy fields close to a fertilizer factory and an industrial zone. In these cases, larger proportions of Cu, Pb, and Zn were found in the exchangeable and acid-soluble fractions compared to the low-metal soils. We conclude that no serious, large-scale heavy metal pollution exists in the Red River Delta. However, there are point pollutions caused by industrial activities and natural sources.     

QTL mapping of fruit nutritional and flavor components in tomato (<Emphasis Type="Italic">Solanum lycopersicum</Emphasis>) using genome-wide SSR markers and recombinant inbred lines (RILs) from an intra-specific cross

Fruit nutritional and flavor components are important targets for breeding new cultivars of tomato (Solanum lycopersicum L.). We developed 108 recombinant inbred lines (the K39 RILs) in the F₆ generation from a cross between two phenotypically different breeding lines, K03 and K09. A linkage map was constructed using 172 genome-wide simple sequence repeat markers, 3 single-nucleotide polymorphism markers, and 2 phenotypic markers. The K39 RIL map consists of 12 linkage groups (LGs) and covers a genetic distance of 1089 cM. We measured the fruit soluble solids content (SSC), titratable acidity (TA), glutamic acid content (GLU), and lycopene content (LYC) of each line in four generations (F₆, F₈, F₁₀, F₁₁), β-carotene content (CAR) in two generations, and pH in one generation. By composite interval mapping that considered yearly variations in components as non-genetic effects, we detected three quantitative trait loci (QTLs) for SSC, four for TA, two for CAR, and one each for GLU, LYC, and pH. Among them, we found two QTLs for TA in LGs 6 and 11, those for GLU and LYC were candidates for novel QTLs. QTLs detected in this study were clustered in five LGs, but we observed no apparent trade-off relationships among the QTLs in each LG. Being derived from an intra-specific cross of tomato breeding materials, these QTLs can be used in practical breeding for improving fruit quality with low risk of linkage drag.     

Performance of Pot-Grown Seedlings of the Dipterocarp Dryobalanops lanceolata with Controlled-Release Fertilizer after Transplantation to the Shifting Cultivation Land in Sarawak, Malaysia

In the present study, the focus was placed on the survival, growth, nutrient status, and ectomycorrhizal formation of pot-grown dipterocarps treated with a controlled-release fertilizer or a chemical fertilizer when transplanted to abandoned shifting cultivation land. Either a chemical fertilizer (CF) or a 700-day controlled-release fertilizer (CRF) had been applied to Dryobalanops lanceolata seedlings at the rates of 0, 2, 5, and 10 g fertilizers per pot in the nursery of the Forest Research Station Niah (FRSN), Miri, Sarawak, Malaysia. The seedlings were cultivated for 18 months in the nursery, and then transplanted to abandoned shifting cultivation land around the FRSN. At 16 months after transplantation, the plants in the CRF treatments showed a good performance in terms of growth and survival ability, because of the sufficient amounts of nutrients accumulated in plants with a sound shoot form and high photosynthetic activity at the nursery stage. On the other hand, many saplings in the CF treatments at the rates of 5 g and 10 g died in the field due to their spindly shoot form and low photosynthetic activity in the nursery, even though the saplings that survived showed on adequate growth. Therefore, the application of slow-release type CRF in the nursery was considered to be feasible and suitable for successful establishment of a dipterocarp plantation in the field. Ectomycorrhizal fungus present in the nursery would sustain and be correlated with P uptake of the saplings after transplantation.